The goals of this research are to apply operant conditioning techniques for the evaluation of toluene as a prototype of solvent abuse. Rats will be exposed periodically to toluene during a critical period of CNS development. Acquisition of a discrimination task, experimentally-induced conflict, and ethanol preference will be studied as a function of early exposure to the solvent. Rats will also be exposed to toluene to determine its effects on an established discrimination task or ethanol preference. Its effects on conflict behavior will delineate its potential anxiolytic action. Behavioral effects of solvent exposure will be correlated with the findings of tissue distribution studies. Ethanol-toluene interaction studies with the juvenile baboon and the match-to-sample discrimination task should determine if inhalant abuse alters the susceptibility of the organism to the effects of ethanol.